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<title>The GNU Fortran Compiler: STRUCTURE and RECORD</title>
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<a name="STRUCTURE-and-RECORD-1"></a>
<h4 class="subsection">6.2.1 <code>STRUCTURE</code> and <code>RECORD</code></h4>
<a name="index-STRUCTURE"></a>
<a name="index-RECORD"></a>
<p>Record structures are a pre-Fortran-90 vendor extension to create
user-defined aggregate data types. GNU Fortran does not support
record structures, only Fortran 90&rsquo;s &ldquo;derived types&rdquo;, which have
a different syntax.
</p>
<p>In many cases, record structures can easily be converted to derived types.
To convert, replace <code>STRUCTURE /</code><var>structure-name</var><code>/</code>
by <code>TYPE</code> <var>type-name</var>. Additionally, replace
<code>RECORD /</code><var>structure-name</var><code>/</code> by
<code>TYPE(</code><var>type-name</var><code>)</code>. Finally, in the component access,
replace the period (<code>.</code>) by the percent sign (<code>%</code>).
</p>
<p>Here is an example of code using the non portable record structure syntax:
</p>
<div class="example">
<pre class="example">! Declaring a structure named ``item'' and containing three fields:
! an integer ID, an description string and a floating-point price.
STRUCTURE /item/
INTEGER id
CHARACTER(LEN=200) description
REAL price
END STRUCTURE
! Define two variables, an single record of type ``item''
! named ``pear'', and an array of items named ``store_catalog''
RECORD /item/ pear, store_catalog(100)
! We can directly access the fields of both variables
pear.id = 92316
pear.description = &quot;juicy D'Anjou pear&quot;
pear.price = 0.15
store_catalog(7).id = 7831
store_catalog(7).description = &quot;milk bottle&quot;
store_catalog(7).price = 1.2
! We can also manipulate the whole structure
store_catalog(12) = pear
print *, store_catalog(12)
</pre></div>
<p>This code can easily be rewritten in the Fortran 90 syntax as following:
</p>
<div class="example">
<pre class="example">! ``STRUCTURE /name/ ... END STRUCTURE'' becomes
! ``TYPE name ... END TYPE''
TYPE item
INTEGER id
CHARACTER(LEN=200) description
REAL price
END TYPE
! ``RECORD /name/ variable'' becomes ``TYPE(name) variable''
TYPE(item) pear, store_catalog(100)
! Instead of using a dot (.) to access fields of a record, the
! standard syntax uses a percent sign (%)
pear%id = 92316
pear%description = &quot;juicy D'Anjou pear&quot;
pear%price = 0.15
store_catalog(7)%id = 7831
store_catalog(7)%description = &quot;milk bottle&quot;
store_catalog(7)%price = 1.2
! Assignments of a whole variable do not change
store_catalog(12) = pear
print *, store_catalog(12)
</pre></div>
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